#include <iostream>
#include <string>

using namespace std;

int main()
{
    int c = 0;
    string s = "()()())";
    string st = "";
    if (s[0] == ')')
    for (char i: s){
    if (i == '(') st = st + i;
    else
        if (st[st.length()-1]) st.pop_back();
    }
    if (st.length() == 0)
        cout << "true";
    else cout << "false";
}
